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Mechanical Engineering

MEMS

A.S. Md Abdul Haseeb

Publication Year

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Nanoindentation And Micro-Mechanical Fracture Toughness Of Electrodeposited Nanocrystalline Ni-W Alloy Films Apr 2012

Nanoindentation And Micro-Mechanical Fracture Toughness Of Electrodeposited Nanocrystalline Ni-W Alloy Films

A.S. Md Abdul Haseeb

Nanocrystalline nickel-tungsten alloys have great potential in the fabrication of components for microelectromechanical systems. Here the fracture toughness of Ni-12.7 at.%W alloy micro-cantilever beams was investigated. Micro-cantilevers were fabricated by UV lithography and electrodeposition and notched by focused ion beam machining. Load was applied using a nanoindenter and fracture toughness was calculated from the fracture load. Fracture toughness of the Ni-12.7 at.%W was in the range of 1.49-5.14 MPa √m. This is higher than the fracture toughness of Si (another important microelectromechanical systems material), but considerably lower than that of electrodeposited nickel and other nickel based alloys. © 2012 Elsevier …


Nanoindentation And Micro-Mechanical Fracture Toughness Of Electrodeposited Nanocrystalline Ni-W Alloy Films Apr 2012

Nanoindentation And Micro-Mechanical Fracture Toughness Of Electrodeposited Nanocrystalline Ni-W Alloy Films

A.S. Md Abdul Haseeb

Nanocrystalline nickel-tungsten alloys have great potential in the fabrication of components for microelectromechanical systems. Here the fracture toughness of Ni-12.7 at.%W alloy micro-cantilever beams was investigated. Micro-cantilevers were fabricated by UV lithography and electrodeposition and notched by focused ion beam machining. Load was applied using a nanoindenter and fracture toughness was calculated from the fracture load. Fracture toughness of the Ni-12.7 at.%W was in the range of 1.49-5.14 MPa √m. This is higher than the fracture toughness of Si (another important microelectromechanical systems material), but considerably lower than that of electrodeposited nickel and other nickel based alloys. © 2012 Elsevier …


Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications Jan 2008

Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications

A.S. Md Abdul Haseeb

For thermally stable LIGA materials for high temperature MEMS applications LIGA Ni-W layers and micro testing samples with different compositions (15 and 5 at% W) were electrodeposited. In order to investigate the thermal stability the Ni-W layers were annealed at different temperatures (300-700°C) and for different durations (1, 4, 16 h). Their microstructure and micro-hardness were than analysed after annealing and compared with those of as-deposited states. The observed microstructures show, in comparison to pure LIGA nickel, a small grain growth and a relatively stable structure up to 700°C. The micro-hardness values of the LIGA Ni-W layers are higher than …